2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
6 * Copyright (C) 1994 - 1999, 2000, 01, 06 Ralf Baechle
7 * Copyright (C) 1995, 1996 Paul M. Antoine
8 * Copyright (C) 1998 Ulf Carlsson
9 * Copyright (C) 1999 Silicon Graphics, Inc.
10 * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
11 * Copyright (C) 2002, 2003, 2004, 2005, 2007 Maciej W. Rozycki
12 * Copyright (C) 2000, 2001, 2012 MIPS Technologies, Inc. All rights reserved.
13 * Copyright (C) 2014, Imagination Technologies Ltd.
15 #include <linux/bitops.h>
16 #include <linux/bug.h>
17 #include <linux/compiler.h>
18 #include <linux/context_tracking.h>
19 #include <linux/cpu_pm.h>
20 #include <linux/kexec.h>
21 #include <linux/init.h>
22 #include <linux/kernel.h>
23 #include <linux/module.h>
25 #include <linux/sched.h>
26 #include <linux/smp.h>
27 #include <linux/spinlock.h>
28 #include <linux/kallsyms.h>
29 #include <linux/bootmem.h>
30 #include <linux/interrupt.h>
31 #include <linux/ptrace.h>
32 #include <linux/kgdb.h>
33 #include <linux/kdebug.h>
34 #include <linux/kprobes.h>
35 #include <linux/notifier.h>
36 #include <linux/kdb.h>
37 #include <linux/irq.h>
38 #include <linux/perf_event.h>
40 #include <asm/bootinfo.h>
41 #include <asm/branch.h>
42 #include <asm/break.h>
45 #include <asm/cpu-type.h>
48 #include <asm/fpu_emulator.h>
50 #include <asm/mips-r2-to-r6-emul.h>
51 #include <asm/mipsregs.h>
52 #include <asm/mipsmtregs.h>
53 #include <asm/module.h>
55 #include <asm/pgtable.h>
56 #include <asm/ptrace.h>
57 #include <asm/sections.h>
58 #include <asm/tlbdebug.h>
59 #include <asm/traps.h>
60 #include <asm/uaccess.h>
61 #include <asm/watch.h>
62 #include <asm/mmu_context.h>
63 #include <asm/types.h>
64 #include <asm/stacktrace.h>
67 extern void check_wait(void);
68 extern asmlinkage void rollback_handle_int(void);
69 extern asmlinkage void handle_int(void);
70 extern u32 handle_tlbl[];
71 extern u32 handle_tlbs[];
72 extern u32 handle_tlbm[];
73 extern asmlinkage void handle_adel(void);
74 extern asmlinkage void handle_ades(void);
75 extern asmlinkage void handle_ibe(void);
76 extern asmlinkage void handle_dbe(void);
77 extern asmlinkage void handle_sys(void);
78 extern asmlinkage void handle_bp(void);
79 extern asmlinkage void handle_ri(void);
80 extern asmlinkage void handle_ri_rdhwr_vivt(void);
81 extern asmlinkage void handle_ri_rdhwr(void);
82 extern asmlinkage void handle_cpu(void);
83 extern asmlinkage void handle_ov(void);
84 extern asmlinkage void handle_tr(void);
85 extern asmlinkage void handle_msa_fpe(void);
86 extern asmlinkage void handle_fpe(void);
87 extern asmlinkage void handle_ftlb(void);
88 extern asmlinkage void handle_msa(void);
89 extern asmlinkage void handle_mdmx(void);
90 extern asmlinkage void handle_watch(void);
91 extern asmlinkage void handle_mt(void);
92 extern asmlinkage void handle_dsp(void);
93 extern asmlinkage void handle_mcheck(void);
94 extern asmlinkage void handle_reserved(void);
95 extern void tlb_do_page_fault_0(void);
97 void (*board_be_init)(void);
98 int (*board_be_handler)(struct pt_regs *regs, int is_fixup);
99 void (*board_nmi_handler_setup)(void);
100 void (*board_ejtag_handler_setup)(void);
101 void (*board_bind_eic_interrupt)(int irq, int regset);
102 void (*board_ebase_setup)(void);
103 void(*board_cache_error_setup)(void);
105 static void show_raw_backtrace(unsigned long reg29)
107 unsigned long *sp = (unsigned long *)(reg29 & ~3);
110 printk("Call Trace:");
111 #ifdef CONFIG_KALLSYMS
114 while (!kstack_end(sp)) {
115 unsigned long __user *p =
116 (unsigned long __user *)(unsigned long)sp++;
117 if (__get_user(addr, p)) {
118 printk(" (Bad stack address)");
121 if (__kernel_text_address(addr))
127 #ifdef CONFIG_KALLSYMS
129 static int __init set_raw_show_trace(char *str)
134 __setup("raw_show_trace", set_raw_show_trace);
137 static void show_backtrace(struct task_struct *task, const struct pt_regs *regs)
139 unsigned long sp = regs->regs[29];
140 unsigned long ra = regs->regs[31];
141 unsigned long pc = regs->cp0_epc;
146 if (raw_show_trace || !__kernel_text_address(pc)) {
147 show_raw_backtrace(sp);
150 printk("Call Trace:\n");
153 pc = unwind_stack(task, &sp, pc, &ra);
159 * This routine abuses get_user()/put_user() to reference pointers
160 * with at least a bit of error checking ...
162 static void show_stacktrace(struct task_struct *task,
163 const struct pt_regs *regs)
165 const int field = 2 * sizeof(unsigned long);
168 unsigned long __user *sp = (unsigned long __user *)regs->regs[29];
172 while ((unsigned long) sp & (PAGE_SIZE - 1)) {
173 if (i && ((i % (64 / field)) == 0))
180 if (__get_user(stackdata, sp++)) {
181 printk(" (Bad stack address)");
185 printk(" %0*lx", field, stackdata);
189 show_backtrace(task, regs);
192 void show_stack(struct task_struct *task, unsigned long *sp)
196 regs.regs[29] = (unsigned long)sp;
200 if (task && task != current) {
201 regs.regs[29] = task->thread.reg29;
203 regs.cp0_epc = task->thread.reg31;
204 #ifdef CONFIG_KGDB_KDB
205 } else if (atomic_read(&kgdb_active) != -1 &&
207 memcpy(®s, kdb_current_regs, sizeof(regs));
208 #endif /* CONFIG_KGDB_KDB */
210 prepare_frametrace(®s);
213 show_stacktrace(task, ®s);
216 static void show_code(unsigned int __user *pc)
219 unsigned short __user *pc16 = NULL;
223 if ((unsigned long)pc & 1)
224 pc16 = (unsigned short __user *)((unsigned long)pc & ~1);
225 for(i = -3 ; i < 6 ; i++) {
227 if (pc16 ? __get_user(insn, pc16 + i) : __get_user(insn, pc + i)) {
228 printk(" (Bad address in epc)\n");
231 printk("%c%0*x%c", (i?' ':'<'), pc16 ? 4 : 8, insn, (i?' ':'>'));
235 static void __show_regs(const struct pt_regs *regs)
237 const int field = 2 * sizeof(unsigned long);
238 unsigned int cause = regs->cp0_cause;
241 show_regs_print_info(KERN_DEFAULT);
244 * Saved main processor registers
246 for (i = 0; i < 32; ) {
250 printk(" %0*lx", field, 0UL);
251 else if (i == 26 || i == 27)
252 printk(" %*s", field, "");
254 printk(" %0*lx", field, regs->regs[i]);
261 #ifdef CONFIG_CPU_HAS_SMARTMIPS
262 printk("Acx : %0*lx\n", field, regs->acx);
264 printk("Hi : %0*lx\n", field, regs->hi);
265 printk("Lo : %0*lx\n", field, regs->lo);
268 * Saved cp0 registers
270 printk("epc : %0*lx %pS\n", field, regs->cp0_epc,
271 (void *) regs->cp0_epc);
272 printk(" %s\n", print_tainted());
273 printk("ra : %0*lx %pS\n", field, regs->regs[31],
274 (void *) regs->regs[31]);
276 printk("Status: %08x ", (uint32_t) regs->cp0_status);
279 if (regs->cp0_status & ST0_KUO)
281 if (regs->cp0_status & ST0_IEO)
283 if (regs->cp0_status & ST0_KUP)
285 if (regs->cp0_status & ST0_IEP)
287 if (regs->cp0_status & ST0_KUC)
289 if (regs->cp0_status & ST0_IEC)
291 } else if (cpu_has_4kex) {
292 if (regs->cp0_status & ST0_KX)
294 if (regs->cp0_status & ST0_SX)
296 if (regs->cp0_status & ST0_UX)
298 switch (regs->cp0_status & ST0_KSU) {
303 printk("SUPERVISOR ");
312 if (regs->cp0_status & ST0_ERL)
314 if (regs->cp0_status & ST0_EXL)
316 if (regs->cp0_status & ST0_IE)
321 printk("Cause : %08x\n", cause);
323 cause = (cause & CAUSEF_EXCCODE) >> CAUSEB_EXCCODE;
324 if (1 <= cause && cause <= 5)
325 printk("BadVA : %0*lx\n", field, regs->cp0_badvaddr);
327 printk("PrId : %08x (%s)\n", read_c0_prid(),
332 * FIXME: really the generic show_regs should take a const pointer argument.
334 void show_regs(struct pt_regs *regs)
336 __show_regs((struct pt_regs *)regs);
339 void show_registers(struct pt_regs *regs)
341 const int field = 2 * sizeof(unsigned long);
342 mm_segment_t old_fs = get_fs();
346 printk("Process %s (pid: %d, threadinfo=%p, task=%p, tls=%0*lx)\n",
347 current->comm, current->pid, current_thread_info(), current,
348 field, current_thread_info()->tp_value);
349 if (cpu_has_userlocal) {
352 tls = read_c0_userlocal();
353 if (tls != current_thread_info()->tp_value)
354 printk("*HwTLS: %0*lx\n", field, tls);
357 if (!user_mode(regs))
358 /* Necessary for getting the correct stack content */
360 show_stacktrace(current, regs);
361 show_code((unsigned int __user *) regs->cp0_epc);
366 static int regs_to_trapnr(struct pt_regs *regs)
368 return (regs->cp0_cause >> 2) & 0x1f;
371 static DEFINE_RAW_SPINLOCK(die_lock);
373 void __noreturn die(const char *str, struct pt_regs *regs)
375 static int die_counter;
380 if (notify_die(DIE_OOPS, str, regs, 0, regs_to_trapnr(regs),
381 SIGSEGV) == NOTIFY_STOP)
385 raw_spin_lock_irq(&die_lock);
388 printk("%s[#%d]:\n", str, ++die_counter);
389 show_registers(regs);
390 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
391 raw_spin_unlock_irq(&die_lock);
396 panic("Fatal exception in interrupt");
399 printk(KERN_EMERG "Fatal exception: panic in 5 seconds");
401 panic("Fatal exception");
404 if (regs && kexec_should_crash(current))
410 extern struct exception_table_entry __start___dbe_table[];
411 extern struct exception_table_entry __stop___dbe_table[];
414 " .section __dbe_table, \"a\"\n"
417 /* Given an address, look for it in the exception tables. */
418 static const struct exception_table_entry *search_dbe_tables(unsigned long addr)
420 const struct exception_table_entry *e;
422 e = search_extable(__start___dbe_table, __stop___dbe_table - 1, addr);
424 e = search_module_dbetables(addr);
428 asmlinkage void do_be(struct pt_regs *regs)
430 const int field = 2 * sizeof(unsigned long);
431 const struct exception_table_entry *fixup = NULL;
432 int data = regs->cp0_cause & 4;
433 int action = MIPS_BE_FATAL;
434 enum ctx_state prev_state;
436 prev_state = exception_enter();
437 /* XXX For now. Fixme, this searches the wrong table ... */
438 if (data && !user_mode(regs))
439 fixup = search_dbe_tables(exception_epc(regs));
442 action = MIPS_BE_FIXUP;
444 if (board_be_handler)
445 action = board_be_handler(regs, fixup != NULL);
448 case MIPS_BE_DISCARD:
452 regs->cp0_epc = fixup->nextinsn;
461 * Assume it would be too dangerous to continue ...
463 printk(KERN_ALERT "%s bus error, epc == %0*lx, ra == %0*lx\n",
464 data ? "Data" : "Instruction",
465 field, regs->cp0_epc, field, regs->regs[31]);
466 if (notify_die(DIE_OOPS, "bus error", regs, 0, regs_to_trapnr(regs),
467 SIGBUS) == NOTIFY_STOP)
470 die_if_kernel("Oops", regs);
471 force_sig(SIGBUS, current);
474 exception_exit(prev_state);
478 * ll/sc, rdhwr, sync emulation
481 #define OPCODE 0xfc000000
482 #define BASE 0x03e00000
483 #define RT 0x001f0000
484 #define OFFSET 0x0000ffff
485 #define LL 0xc0000000
486 #define SC 0xe0000000
487 #define SPEC0 0x00000000
488 #define SPEC3 0x7c000000
489 #define RD 0x0000f800
490 #define FUNC 0x0000003f
491 #define SYNC 0x0000000f
492 #define RDHWR 0x0000003b
494 /* microMIPS definitions */
495 #define MM_POOL32A_FUNC 0xfc00ffff
496 #define MM_RDHWR 0x00006b3c
497 #define MM_RS 0x001f0000
498 #define MM_RT 0x03e00000
501 * The ll_bit is cleared by r*_switch.S
505 struct task_struct *ll_task;
507 static inline int simulate_ll(struct pt_regs *regs, unsigned int opcode)
509 unsigned long value, __user *vaddr;
513 * analyse the ll instruction that just caused a ri exception
514 * and put the referenced address to addr.
517 /* sign extend offset */
518 offset = opcode & OFFSET;
522 vaddr = (unsigned long __user *)
523 ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
525 if ((unsigned long)vaddr & 3)
527 if (get_user(value, vaddr))
532 if (ll_task == NULL || ll_task == current) {
541 regs->regs[(opcode & RT) >> 16] = value;
546 static inline int simulate_sc(struct pt_regs *regs, unsigned int opcode)
548 unsigned long __user *vaddr;
553 * analyse the sc instruction that just caused a ri exception
554 * and put the referenced address to addr.
557 /* sign extend offset */
558 offset = opcode & OFFSET;
562 vaddr = (unsigned long __user *)
563 ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
564 reg = (opcode & RT) >> 16;
566 if ((unsigned long)vaddr & 3)
571 if (ll_bit == 0 || ll_task != current) {
579 if (put_user(regs->regs[reg], vaddr))
588 * ll uses the opcode of lwc0 and sc uses the opcode of swc0. That is both
589 * opcodes are supposed to result in coprocessor unusable exceptions if
590 * executed on ll/sc-less processors. That's the theory. In practice a
591 * few processors such as NEC's VR4100 throw reserved instruction exceptions
592 * instead, so we're doing the emulation thing in both exception handlers.
594 static int simulate_llsc(struct pt_regs *regs, unsigned int opcode)
596 if ((opcode & OPCODE) == LL) {
597 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
599 return simulate_ll(regs, opcode);
601 if ((opcode & OPCODE) == SC) {
602 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
604 return simulate_sc(regs, opcode);
607 return -1; /* Must be something else ... */
611 * Simulate trapping 'rdhwr' instructions to provide user accessible
612 * registers not implemented in hardware.
614 static int simulate_rdhwr(struct pt_regs *regs, int rd, int rt)
616 struct thread_info *ti = task_thread_info(current);
618 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
621 case 0: /* CPU number */
622 regs->regs[rt] = smp_processor_id();
624 case 1: /* SYNCI length */
625 regs->regs[rt] = min(current_cpu_data.dcache.linesz,
626 current_cpu_data.icache.linesz);
628 case 2: /* Read count register */
629 regs->regs[rt] = read_c0_count();
631 case 3: /* Count register resolution */
632 switch (current_cpu_type()) {
642 regs->regs[rt] = ti->tp_value;
649 static int simulate_rdhwr_normal(struct pt_regs *regs, unsigned int opcode)
651 if ((opcode & OPCODE) == SPEC3 && (opcode & FUNC) == RDHWR) {
652 int rd = (opcode & RD) >> 11;
653 int rt = (opcode & RT) >> 16;
655 simulate_rdhwr(regs, rd, rt);
663 static int simulate_rdhwr_mm(struct pt_regs *regs, unsigned short opcode)
665 if ((opcode & MM_POOL32A_FUNC) == MM_RDHWR) {
666 int rd = (opcode & MM_RS) >> 16;
667 int rt = (opcode & MM_RT) >> 21;
668 simulate_rdhwr(regs, rd, rt);
676 static int simulate_sync(struct pt_regs *regs, unsigned int opcode)
678 if ((opcode & OPCODE) == SPEC0 && (opcode & FUNC) == SYNC) {
679 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
684 return -1; /* Must be something else ... */
687 asmlinkage void do_ov(struct pt_regs *regs)
689 enum ctx_state prev_state;
692 prev_state = exception_enter();
693 die_if_kernel("Integer overflow", regs);
695 info.si_code = FPE_INTOVF;
696 info.si_signo = SIGFPE;
698 info.si_addr = (void __user *) regs->cp0_epc;
699 force_sig_info(SIGFPE, &info, current);
700 exception_exit(prev_state);
703 int process_fpemu_return(int sig, void __user *fault_addr)
705 if (sig == SIGSEGV || sig == SIGBUS) {
706 struct siginfo si = {0};
707 si.si_addr = fault_addr;
709 if (sig == SIGSEGV) {
710 down_read(¤t->mm->mmap_sem);
711 if (find_vma(current->mm, (unsigned long)fault_addr))
712 si.si_code = SEGV_ACCERR;
714 si.si_code = SEGV_MAPERR;
715 up_read(¤t->mm->mmap_sem);
717 si.si_code = BUS_ADRERR;
719 force_sig_info(sig, &si, current);
722 force_sig(sig, current);
729 static int simulate_fp(struct pt_regs *regs, unsigned int opcode,
730 unsigned long old_epc, unsigned long old_ra)
732 union mips_instruction inst = { .word = opcode };
733 void __user *fault_addr = NULL;
736 /* If it's obviously not an FP instruction, skip it */
737 switch (inst.i_format.opcode) {
751 * do_ri skipped over the instruction via compute_return_epc, undo
752 * that for the FPU emulator.
754 regs->cp0_epc = old_epc;
755 regs->regs[31] = old_ra;
757 /* Save the FP context to struct thread_struct */
760 /* Run the emulator */
761 sig = fpu_emulator_cop1Handler(regs, ¤t->thread.fpu, 1,
764 /* If something went wrong, signal */
765 process_fpemu_return(sig, fault_addr);
767 /* Restore the hardware register state */
774 * XXX Delayed fp exceptions when doing a lazy ctx switch XXX
776 asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
778 enum ctx_state prev_state;
779 siginfo_t info = {0};
781 prev_state = exception_enter();
782 if (notify_die(DIE_FP, "FP exception", regs, 0, regs_to_trapnr(regs),
783 SIGFPE) == NOTIFY_STOP)
785 die_if_kernel("FP exception in kernel code", regs);
787 if (fcr31 & FPU_CSR_UNI_X) {
789 void __user *fault_addr = NULL;
792 * Unimplemented operation exception. If we've got the full
793 * software emulator on-board, let's use it...
795 * Force FPU to dump state into task/thread context. We're
796 * moving a lot of data here for what is probably a single
797 * instruction, but the alternative is to pre-decode the FP
798 * register operands before invoking the emulator, which seems
799 * a bit extreme for what should be an infrequent event.
801 /* Ensure 'resume' not overwrite saved fp context again. */
804 /* Run the emulator */
805 sig = fpu_emulator_cop1Handler(regs, ¤t->thread.fpu, 1,
809 * We can't allow the emulated instruction to leave any of
810 * the cause bit set in $fcr31.
812 current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
814 /* Restore the hardware register state */
815 own_fpu(1); /* Using the FPU again. */
817 /* If something went wrong, signal */
818 process_fpemu_return(sig, fault_addr);
824 * Inexact can happen together with Overflow or Underflow.
825 * Respect the mask to deliver the correct exception.
827 fcr31 &= (fcr31 & FPU_CSR_ALL_E) <<
828 (ffs(FPU_CSR_ALL_X) - ffs(FPU_CSR_ALL_E));
829 if (fcr31 & FPU_CSR_INV_X)
830 info.si_code = FPE_FLTINV;
831 else if (fcr31 & FPU_CSR_DIV_X)
832 info.si_code = FPE_FLTDIV;
833 else if (fcr31 & FPU_CSR_OVF_X)
834 info.si_code = FPE_FLTOVF;
835 else if (fcr31 & FPU_CSR_UDF_X)
836 info.si_code = FPE_FLTUND;
837 else if (fcr31 & FPU_CSR_INE_X)
838 info.si_code = FPE_FLTRES;
840 info.si_code = __SI_FAULT;
841 info.si_signo = SIGFPE;
843 info.si_addr = (void __user *) regs->cp0_epc;
844 force_sig_info(SIGFPE, &info, current);
847 exception_exit(prev_state);
850 void do_trap_or_bp(struct pt_regs *regs, unsigned int code,
856 #ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
857 if (kgdb_ll_trap(DIE_TRAP, str, regs, code, regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
859 #endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
861 if (notify_die(DIE_TRAP, str, regs, code, regs_to_trapnr(regs),
862 SIGTRAP) == NOTIFY_STOP)
866 * A short test says that IRIX 5.3 sends SIGTRAP for all trap
867 * insns, even for trap and break codes that indicate arithmetic
868 * failures. Weird ...
869 * But should we continue the brokenness??? --macro
874 scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
875 die_if_kernel(b, regs);
876 if (code == BRK_DIVZERO)
877 info.si_code = FPE_INTDIV;
879 info.si_code = FPE_INTOVF;
880 info.si_signo = SIGFPE;
882 info.si_addr = (void __user *) regs->cp0_epc;
883 force_sig_info(SIGFPE, &info, current);
886 die_if_kernel("Kernel bug detected", regs);
887 force_sig(SIGTRAP, current);
891 * This breakpoint code is used by the FPU emulator to retake
892 * control of the CPU after executing the instruction from the
893 * delay slot of an emulated branch.
895 * Terminate if exception was recognized as a delay slot return
896 * otherwise handle as normal.
898 if (do_dsemulret(regs))
901 die_if_kernel("Math emu break/trap", regs);
902 force_sig(SIGTRAP, current);
905 scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
906 die_if_kernel(b, regs);
907 force_sig(SIGTRAP, current);
911 asmlinkage void do_bp(struct pt_regs *regs)
913 unsigned long epc = msk_isa16_mode(exception_epc(regs));
914 unsigned int opcode, bcode;
915 enum ctx_state prev_state;
919 if (!user_mode(regs))
922 prev_state = exception_enter();
923 if (get_isa16_mode(regs->cp0_epc)) {
926 if (__get_user(instr[0], (u16 __user *)epc))
929 if (!cpu_has_mmips) {
931 bcode = (instr[0] >> 5) & 0x3f;
932 } else if (mm_insn_16bit(instr[0])) {
933 /* 16-bit microMIPS BREAK */
934 bcode = instr[0] & 0xf;
936 /* 32-bit microMIPS BREAK */
937 if (__get_user(instr[1], (u16 __user *)(epc + 2)))
939 opcode = (instr[0] << 16) | instr[1];
940 bcode = (opcode >> 6) & ((1 << 20) - 1);
943 if (__get_user(opcode, (unsigned int __user *)epc))
945 bcode = (opcode >> 6) & ((1 << 20) - 1);
949 * There is the ancient bug in the MIPS assemblers that the break
950 * code starts left to bit 16 instead to bit 6 in the opcode.
951 * Gas is bug-compatible, but not always, grrr...
952 * We handle both cases with a simple heuristics. --macro
954 if (bcode >= (1 << 10))
955 bcode = ((bcode & ((1 << 10) - 1)) << 10) | (bcode >> 10);
958 * notify the kprobe handlers, if instruction is likely to
963 if (notify_die(DIE_BREAK, "debug", regs, bcode,
964 regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
968 case BRK_KPROBE_SSTEPBP:
969 if (notify_die(DIE_SSTEPBP, "single_step", regs, bcode,
970 regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
978 do_trap_or_bp(regs, bcode, "Break");
982 exception_exit(prev_state);
986 force_sig(SIGSEGV, current);
990 asmlinkage void do_tr(struct pt_regs *regs)
992 u32 opcode, tcode = 0;
993 enum ctx_state prev_state;
996 unsigned long epc = msk_isa16_mode(exception_epc(regs));
999 if (!user_mode(regs))
1002 prev_state = exception_enter();
1003 if (get_isa16_mode(regs->cp0_epc)) {
1004 if (__get_user(instr[0], (u16 __user *)(epc + 0)) ||
1005 __get_user(instr[1], (u16 __user *)(epc + 2)))
1007 opcode = (instr[0] << 16) | instr[1];
1008 /* Immediate versions don't provide a code. */
1009 if (!(opcode & OPCODE))
1010 tcode = (opcode >> 12) & ((1 << 4) - 1);
1012 if (__get_user(opcode, (u32 __user *)epc))
1014 /* Immediate versions don't provide a code. */
1015 if (!(opcode & OPCODE))
1016 tcode = (opcode >> 6) & ((1 << 10) - 1);
1019 do_trap_or_bp(regs, tcode, "Trap");
1023 exception_exit(prev_state);
1027 force_sig(SIGSEGV, current);
1031 asmlinkage void do_ri(struct pt_regs *regs)
1033 unsigned int __user *epc = (unsigned int __user *)exception_epc(regs);
1034 unsigned long old_epc = regs->cp0_epc;
1035 unsigned long old31 = regs->regs[31];
1036 enum ctx_state prev_state;
1037 unsigned int opcode = 0;
1041 * Avoid any kernel code. Just emulate the R2 instruction
1042 * as quickly as possible.
1044 if (mipsr2_emulation && cpu_has_mips_r6 &&
1045 likely(user_mode(regs)) &&
1046 likely(get_user(opcode, epc) >= 0)) {
1047 status = mipsr2_decoder(regs, opcode);
1051 task_thread_info(current)->r2_emul_return = 1;
1056 process_fpemu_return(status,
1057 ¤t->thread.cp0_baduaddr);
1058 task_thread_info(current)->r2_emul_return = 1;
1065 prev_state = exception_enter();
1067 if (notify_die(DIE_RI, "RI Fault", regs, 0, regs_to_trapnr(regs),
1068 SIGILL) == NOTIFY_STOP)
1071 die_if_kernel("Reserved instruction in kernel code", regs);
1073 if (unlikely(compute_return_epc(regs) < 0))
1076 if (get_isa16_mode(regs->cp0_epc)) {
1077 unsigned short mmop[2] = { 0 };
1079 if (unlikely(get_user(mmop[0], epc) < 0))
1081 if (unlikely(get_user(mmop[1], epc) < 0))
1083 opcode = (mmop[0] << 16) | mmop[1];
1086 status = simulate_rdhwr_mm(regs, opcode);
1088 if (unlikely(get_user(opcode, epc) < 0))
1091 if (!cpu_has_llsc && status < 0)
1092 status = simulate_llsc(regs, opcode);
1095 status = simulate_rdhwr_normal(regs, opcode);
1098 status = simulate_sync(regs, opcode);
1101 status = simulate_fp(regs, opcode, old_epc, old31);
1107 if (unlikely(status > 0)) {
1108 regs->cp0_epc = old_epc; /* Undo skip-over. */
1109 regs->regs[31] = old31;
1110 force_sig(status, current);
1114 exception_exit(prev_state);
1118 * MIPS MT processors may have fewer FPU contexts than CPU threads. If we've
1119 * emulated more than some threshold number of instructions, force migration to
1120 * a "CPU" that has FP support.
1122 static void mt_ase_fp_affinity(void)
1124 #ifdef CONFIG_MIPS_MT_FPAFF
1125 if (mt_fpemul_threshold > 0 &&
1126 ((current->thread.emulated_fp++ > mt_fpemul_threshold))) {
1128 * If there's no FPU present, or if the application has already
1129 * restricted the allowed set to exclude any CPUs with FPUs,
1130 * we'll skip the procedure.
1132 if (cpus_intersects(current->cpus_allowed, mt_fpu_cpumask)) {
1135 current->thread.user_cpus_allowed
1136 = current->cpus_allowed;
1137 cpus_and(tmask, current->cpus_allowed,
1139 set_cpus_allowed_ptr(current, &tmask);
1140 set_thread_flag(TIF_FPUBOUND);
1143 #endif /* CONFIG_MIPS_MT_FPAFF */
1147 * No lock; only written during early bootup by CPU 0.
1149 static RAW_NOTIFIER_HEAD(cu2_chain);
1151 int __ref register_cu2_notifier(struct notifier_block *nb)
1153 return raw_notifier_chain_register(&cu2_chain, nb);
1156 int cu2_notifier_call_chain(unsigned long val, void *v)
1158 return raw_notifier_call_chain(&cu2_chain, val, v);
1161 static int default_cu2_call(struct notifier_block *nfb, unsigned long action,
1164 struct pt_regs *regs = data;
1166 die_if_kernel("COP2: Unhandled kernel unaligned access or invalid "
1167 "instruction", regs);
1168 force_sig(SIGILL, current);
1173 static int wait_on_fp_mode_switch(atomic_t *p)
1176 * The FP mode for this task is currently being switched. That may
1177 * involve modifications to the format of this tasks FP context which
1178 * make it unsafe to proceed with execution for the moment. Instead,
1179 * schedule some other task.
1185 static int enable_restore_fp_context(int msa)
1187 int err, was_fpu_owner, prior_msa;
1190 * If an FP mode switch is currently underway, wait for it to
1191 * complete before proceeding.
1193 wait_on_atomic_t(¤t->mm->context.fp_mode_switching,
1194 wait_on_fp_mode_switch, TASK_KILLABLE);
1197 /* First time FP context user. */
1203 set_thread_flag(TIF_USEDMSA);
1204 set_thread_flag(TIF_MSA_CTX_LIVE);
1213 * This task has formerly used the FP context.
1215 * If this thread has no live MSA vector context then we can simply
1216 * restore the scalar FP context. If it has live MSA vector context
1217 * (that is, it has or may have used MSA since last performing a
1218 * function call) then we'll need to restore the vector context. This
1219 * applies even if we're currently only executing a scalar FP
1220 * instruction. This is because if we were to later execute an MSA
1221 * instruction then we'd either have to:
1223 * - Restore the vector context & clobber any registers modified by
1224 * scalar FP instructions between now & then.
1228 * - Not restore the vector context & lose the most significant bits
1229 * of all vector registers.
1231 * Neither of those options is acceptable. We cannot restore the least
1232 * significant bits of the registers now & only restore the most
1233 * significant bits later because the most significant bits of any
1234 * vector registers whose aliased FP register is modified now will have
1235 * been zeroed. We'd have no way to know that when restoring the vector
1236 * context & thus may load an outdated value for the most significant
1237 * bits of a vector register.
1239 if (!msa && !thread_msa_context_live())
1243 * This task is using or has previously used MSA. Thus we require
1244 * that Status.FR == 1.
1247 was_fpu_owner = is_fpu_owner();
1248 err = own_fpu_inatomic(0);
1253 write_msa_csr(current->thread.fpu.msacsr);
1254 set_thread_flag(TIF_USEDMSA);
1257 * If this is the first time that the task is using MSA and it has
1258 * previously used scalar FP in this time slice then we already nave
1259 * FP context which we shouldn't clobber. We do however need to clear
1260 * the upper 64b of each vector register so that this task has no
1261 * opportunity to see data left behind by another.
1263 prior_msa = test_and_set_thread_flag(TIF_MSA_CTX_LIVE);
1264 if (!prior_msa && was_fpu_owner) {
1272 * Restore the least significant 64b of each vector register
1273 * from the existing scalar FP context.
1275 _restore_fp(current);
1278 * The task has not formerly used MSA, so clear the upper 64b
1279 * of each vector register such that it cannot see data left
1280 * behind by another task.
1284 /* We need to restore the vector context. */
1285 restore_msa(current);
1287 /* Restore the scalar FP control & status register */
1289 write_32bit_cp1_register(CP1_STATUS,
1290 current->thread.fpu.fcr31);
1299 asmlinkage void do_cpu(struct pt_regs *regs)
1301 enum ctx_state prev_state;
1302 unsigned int __user *epc;
1303 unsigned long old_epc, old31;
1304 unsigned int opcode;
1307 unsigned long __maybe_unused flags;
1309 prev_state = exception_enter();
1310 cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
1313 die_if_kernel("do_cpu invoked from kernel context!", regs);
1317 epc = (unsigned int __user *)exception_epc(regs);
1318 old_epc = regs->cp0_epc;
1319 old31 = regs->regs[31];
1323 if (unlikely(compute_return_epc(regs) < 0))
1326 if (get_isa16_mode(regs->cp0_epc)) {
1327 unsigned short mmop[2] = { 0 };
1329 if (unlikely(get_user(mmop[0], epc) < 0))
1331 if (unlikely(get_user(mmop[1], epc) < 0))
1333 opcode = (mmop[0] << 16) | mmop[1];
1336 status = simulate_rdhwr_mm(regs, opcode);
1338 if (unlikely(get_user(opcode, epc) < 0))
1341 if (!cpu_has_llsc && status < 0)
1342 status = simulate_llsc(regs, opcode);
1345 status = simulate_rdhwr_normal(regs, opcode);
1351 if (unlikely(status > 0)) {
1352 regs->cp0_epc = old_epc; /* Undo skip-over. */
1353 regs->regs[31] = old31;
1354 force_sig(status, current);
1361 * The COP3 opcode space and consequently the CP0.Status.CU3
1362 * bit and the CP0.Cause.CE=3 encoding have been removed as
1363 * of the MIPS III ISA. From the MIPS IV and MIPS32r2 ISAs
1364 * up the space has been reused for COP1X instructions, that
1365 * are enabled by the CP0.Status.CU1 bit and consequently
1366 * use the CP0.Cause.CE=1 encoding for Coprocessor Unusable
1367 * exceptions. Some FPU-less processors that implement one
1368 * of these ISAs however use this code erroneously for COP1X
1369 * instructions. Therefore we redirect this trap to the FP
1372 if (raw_cpu_has_fpu || !cpu_has_mips_4_5_64_r2_r6) {
1373 force_sig(SIGILL, current);
1379 err = enable_restore_fp_context(0);
1381 if (!raw_cpu_has_fpu || err) {
1383 void __user *fault_addr = NULL;
1384 sig = fpu_emulator_cop1Handler(regs,
1385 ¤t->thread.fpu,
1387 if (!process_fpemu_return(sig, fault_addr) && !err)
1388 mt_ase_fp_affinity();
1394 raw_notifier_call_chain(&cu2_chain, CU2_EXCEPTION, regs);
1398 exception_exit(prev_state);
1401 asmlinkage void do_msa_fpe(struct pt_regs *regs)
1403 enum ctx_state prev_state;
1405 prev_state = exception_enter();
1406 die_if_kernel("do_msa_fpe invoked from kernel context!", regs);
1407 force_sig(SIGFPE, current);
1408 exception_exit(prev_state);
1411 asmlinkage void do_msa(struct pt_regs *regs)
1413 enum ctx_state prev_state;
1416 prev_state = exception_enter();
1418 if (!cpu_has_msa || test_thread_flag(TIF_32BIT_FPREGS)) {
1419 force_sig(SIGILL, current);
1423 die_if_kernel("do_msa invoked from kernel context!", regs);
1425 err = enable_restore_fp_context(1);
1427 force_sig(SIGILL, current);
1429 exception_exit(prev_state);
1432 asmlinkage void do_mdmx(struct pt_regs *regs)
1434 enum ctx_state prev_state;
1436 prev_state = exception_enter();
1437 force_sig(SIGILL, current);
1438 exception_exit(prev_state);
1442 * Called with interrupts disabled.
1444 asmlinkage void do_watch(struct pt_regs *regs)
1446 enum ctx_state prev_state;
1449 prev_state = exception_enter();
1451 * Clear WP (bit 22) bit of cause register so we don't loop
1454 cause = read_c0_cause();
1455 cause &= ~(1 << 22);
1456 write_c0_cause(cause);
1459 * If the current thread has the watch registers loaded, save
1460 * their values and send SIGTRAP. Otherwise another thread
1461 * left the registers set, clear them and continue.
1463 if (test_tsk_thread_flag(current, TIF_LOAD_WATCH)) {
1464 mips_read_watch_registers();
1466 force_sig(SIGTRAP, current);
1468 mips_clear_watch_registers();
1471 exception_exit(prev_state);
1474 asmlinkage void do_mcheck(struct pt_regs *regs)
1476 const int field = 2 * sizeof(unsigned long);
1477 int multi_match = regs->cp0_status & ST0_TS;
1478 enum ctx_state prev_state;
1480 prev_state = exception_enter();
1484 pr_err("Index : %0x\n", read_c0_index());
1485 pr_err("Pagemask: %0x\n", read_c0_pagemask());
1486 pr_err("EntryHi : %0*lx\n", field, read_c0_entryhi());
1487 pr_err("EntryLo0: %0*lx\n", field, read_c0_entrylo0());
1488 pr_err("EntryLo1: %0*lx\n", field, read_c0_entrylo1());
1489 pr_err("Wired : %0x\n", read_c0_wired());
1490 pr_err("Pagegrain: %0x\n", read_c0_pagegrain());
1492 pr_err("PWField : %0*lx\n", field, read_c0_pwfield());
1493 pr_err("PWSize : %0*lx\n", field, read_c0_pwsize());
1494 pr_err("PWCtl : %0x\n", read_c0_pwctl());
1500 show_code((unsigned int __user *) regs->cp0_epc);
1503 * Some chips may have other causes of machine check (e.g. SB1
1506 panic("Caught Machine Check exception - %scaused by multiple "
1507 "matching entries in the TLB.",
1508 (multi_match) ? "" : "not ");
1511 asmlinkage void do_mt(struct pt_regs *regs)
1515 subcode = (read_vpe_c0_vpecontrol() & VPECONTROL_EXCPT)
1516 >> VPECONTROL_EXCPT_SHIFT;
1519 printk(KERN_DEBUG "Thread Underflow\n");
1522 printk(KERN_DEBUG "Thread Overflow\n");
1525 printk(KERN_DEBUG "Invalid YIELD Qualifier\n");
1528 printk(KERN_DEBUG "Gating Storage Exception\n");
1531 printk(KERN_DEBUG "YIELD Scheduler Exception\n");
1534 printk(KERN_DEBUG "Gating Storage Scheduler Exception\n");
1537 printk(KERN_DEBUG "*** UNKNOWN THREAD EXCEPTION %d ***\n",
1541 die_if_kernel("MIPS MT Thread exception in kernel", regs);
1543 force_sig(SIGILL, current);
1547 asmlinkage void do_dsp(struct pt_regs *regs)
1550 panic("Unexpected DSP exception");
1552 force_sig(SIGILL, current);
1555 asmlinkage void do_reserved(struct pt_regs *regs)
1558 * Game over - no way to handle this if it ever occurs. Most probably
1559 * caused by a new unknown cpu type or after another deadly
1560 * hard/software error.
1563 panic("Caught reserved exception %ld - should not happen.",
1564 (regs->cp0_cause & 0x7f) >> 2);
1567 static int __initdata l1parity = 1;
1568 static int __init nol1parity(char *s)
1573 __setup("nol1par", nol1parity);
1574 static int __initdata l2parity = 1;
1575 static int __init nol2parity(char *s)
1580 __setup("nol2par", nol2parity);
1583 * Some MIPS CPUs can enable/disable for cache parity detection, but do
1584 * it different ways.
1586 static inline void parity_protection_init(void)
1588 switch (current_cpu_type()) {
1594 case CPU_INTERAPTIV:
1597 case CPU_QEMU_GENERIC:
1599 #define ERRCTL_PE 0x80000000
1600 #define ERRCTL_L2P 0x00800000
1601 unsigned long errctl;
1602 unsigned int l1parity_present, l2parity_present;
1604 errctl = read_c0_ecc();
1605 errctl &= ~(ERRCTL_PE|ERRCTL_L2P);
1607 /* probe L1 parity support */
1608 write_c0_ecc(errctl | ERRCTL_PE);
1609 back_to_back_c0_hazard();
1610 l1parity_present = (read_c0_ecc() & ERRCTL_PE);
1612 /* probe L2 parity support */
1613 write_c0_ecc(errctl|ERRCTL_L2P);
1614 back_to_back_c0_hazard();
1615 l2parity_present = (read_c0_ecc() & ERRCTL_L2P);
1617 if (l1parity_present && l2parity_present) {
1619 errctl |= ERRCTL_PE;
1620 if (l1parity ^ l2parity)
1621 errctl |= ERRCTL_L2P;
1622 } else if (l1parity_present) {
1624 errctl |= ERRCTL_PE;
1625 } else if (l2parity_present) {
1627 errctl |= ERRCTL_L2P;
1629 /* No parity available */
1632 printk(KERN_INFO "Writing ErrCtl register=%08lx\n", errctl);
1634 write_c0_ecc(errctl);
1635 back_to_back_c0_hazard();
1636 errctl = read_c0_ecc();
1637 printk(KERN_INFO "Readback ErrCtl register=%08lx\n", errctl);
1639 if (l1parity_present)
1640 printk(KERN_INFO "Cache parity protection %sabled\n",
1641 (errctl & ERRCTL_PE) ? "en" : "dis");
1643 if (l2parity_present) {
1644 if (l1parity_present && l1parity)
1645 errctl ^= ERRCTL_L2P;
1646 printk(KERN_INFO "L2 cache parity protection %sabled\n",
1647 (errctl & ERRCTL_L2P) ? "en" : "dis");
1655 write_c0_ecc(0x80000000);
1656 back_to_back_c0_hazard();
1657 /* Set the PE bit (bit 31) in the c0_errctl register. */
1658 printk(KERN_INFO "Cache parity protection %sabled\n",
1659 (read_c0_ecc() & 0x80000000) ? "en" : "dis");
1663 /* Clear the DE bit (bit 16) in the c0_status register. */
1664 printk(KERN_INFO "Enable cache parity protection for "
1665 "MIPS 20KC/25KF CPUs.\n");
1666 clear_c0_status(ST0_DE);
1673 asmlinkage void cache_parity_error(void)
1675 const int field = 2 * sizeof(unsigned long);
1676 unsigned int reg_val;
1678 /* For the moment, report the problem and hang. */
1679 printk("Cache error exception:\n");
1680 printk("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
1681 reg_val = read_c0_cacheerr();
1682 printk("c0_cacheerr == %08x\n", reg_val);
1684 printk("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
1685 reg_val & (1<<30) ? "secondary" : "primary",
1686 reg_val & (1<<31) ? "data" : "insn");
1687 if ((cpu_has_mips_r2_r6) &&
1688 ((current_cpu_data.processor_id & 0xff0000) == PRID_COMP_MIPS)) {
1689 pr_err("Error bits: %s%s%s%s%s%s%s%s\n",
1690 reg_val & (1<<29) ? "ED " : "",
1691 reg_val & (1<<28) ? "ET " : "",
1692 reg_val & (1<<27) ? "ES " : "",
1693 reg_val & (1<<26) ? "EE " : "",
1694 reg_val & (1<<25) ? "EB " : "",
1695 reg_val & (1<<24) ? "EI " : "",
1696 reg_val & (1<<23) ? "E1 " : "",
1697 reg_val & (1<<22) ? "E0 " : "");
1699 pr_err("Error bits: %s%s%s%s%s%s%s\n",
1700 reg_val & (1<<29) ? "ED " : "",
1701 reg_val & (1<<28) ? "ET " : "",
1702 reg_val & (1<<26) ? "EE " : "",
1703 reg_val & (1<<25) ? "EB " : "",
1704 reg_val & (1<<24) ? "EI " : "",
1705 reg_val & (1<<23) ? "E1 " : "",
1706 reg_val & (1<<22) ? "E0 " : "");
1708 printk("IDX: 0x%08x\n", reg_val & ((1<<22)-1));
1710 #if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
1711 if (reg_val & (1<<22))
1712 printk("DErrAddr0: 0x%0*lx\n", field, read_c0_derraddr0());
1714 if (reg_val & (1<<23))
1715 printk("DErrAddr1: 0x%0*lx\n", field, read_c0_derraddr1());
1718 panic("Can't handle the cache error!");
1721 asmlinkage void do_ftlb(void)
1723 const int field = 2 * sizeof(unsigned long);
1724 unsigned int reg_val;
1726 /* For the moment, report the problem and hang. */
1727 if ((cpu_has_mips_r2_r6) &&
1728 ((current_cpu_data.processor_id & 0xff0000) == PRID_COMP_MIPS)) {
1729 pr_err("FTLB error exception, cp0_ecc=0x%08x:\n",
1731 pr_err("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
1732 reg_val = read_c0_cacheerr();
1733 pr_err("c0_cacheerr == %08x\n", reg_val);
1735 if ((reg_val & 0xc0000000) == 0xc0000000) {
1736 pr_err("Decoded c0_cacheerr: FTLB parity error\n");
1738 pr_err("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
1739 reg_val & (1<<30) ? "secondary" : "primary",
1740 reg_val & (1<<31) ? "data" : "insn");
1743 pr_err("FTLB error exception\n");
1745 /* Just print the cacheerr bits for now */
1746 cache_parity_error();
1750 * SDBBP EJTAG debug exception handler.
1751 * We skip the instruction and return to the next instruction.
1753 void ejtag_exception_handler(struct pt_regs *regs)
1755 const int field = 2 * sizeof(unsigned long);
1756 unsigned long depc, old_epc, old_ra;
1759 printk(KERN_DEBUG "SDBBP EJTAG debug exception - not handled yet, just ignored!\n");
1760 depc = read_c0_depc();
1761 debug = read_c0_debug();
1762 printk(KERN_DEBUG "c0_depc = %0*lx, DEBUG = %08x\n", field, depc, debug);
1763 if (debug & 0x80000000) {
1765 * In branch delay slot.
1766 * We cheat a little bit here and use EPC to calculate the
1767 * debug return address (DEPC). EPC is restored after the
1770 old_epc = regs->cp0_epc;
1771 old_ra = regs->regs[31];
1772 regs->cp0_epc = depc;
1773 compute_return_epc(regs);
1774 depc = regs->cp0_epc;
1775 regs->cp0_epc = old_epc;
1776 regs->regs[31] = old_ra;
1779 write_c0_depc(depc);
1782 printk(KERN_DEBUG "\n\n----- Enable EJTAG single stepping ----\n\n");
1783 write_c0_debug(debug | 0x100);
1788 * NMI exception handler.
1789 * No lock; only written during early bootup by CPU 0.
1791 static RAW_NOTIFIER_HEAD(nmi_chain);
1793 int register_nmi_notifier(struct notifier_block *nb)
1795 return raw_notifier_chain_register(&nmi_chain, nb);
1798 void __noreturn nmi_exception_handler(struct pt_regs *regs)
1802 raw_notifier_call_chain(&nmi_chain, 0, regs);
1804 snprintf(str, 100, "CPU%d NMI taken, CP0_EPC=%lx\n",
1805 smp_processor_id(), regs->cp0_epc);
1806 regs->cp0_epc = read_c0_errorepc();
1810 #define VECTORSPACING 0x100 /* for EI/VI mode */
1812 unsigned long ebase;
1813 unsigned long exception_handlers[32];
1814 unsigned long vi_handlers[64];
1816 void __init *set_except_vector(int n, void *addr)
1818 unsigned long handler = (unsigned long) addr;
1819 unsigned long old_handler;
1821 #ifdef CONFIG_CPU_MICROMIPS
1823 * Only the TLB handlers are cache aligned with an even
1824 * address. All other handlers are on an odd address and
1825 * require no modification. Otherwise, MIPS32 mode will
1826 * be entered when handling any TLB exceptions. That
1827 * would be bad...since we must stay in microMIPS mode.
1829 if (!(handler & 0x1))
1832 old_handler = xchg(&exception_handlers[n], handler);
1834 if (n == 0 && cpu_has_divec) {
1835 #ifdef CONFIG_CPU_MICROMIPS
1836 unsigned long jump_mask = ~((1 << 27) - 1);
1838 unsigned long jump_mask = ~((1 << 28) - 1);
1840 u32 *buf = (u32 *)(ebase + 0x200);
1841 unsigned int k0 = 26;
1842 if ((handler & jump_mask) == ((ebase + 0x200) & jump_mask)) {
1843 uasm_i_j(&buf, handler & ~jump_mask);
1846 UASM_i_LA(&buf, k0, handler);
1847 uasm_i_jr(&buf, k0);
1850 local_flush_icache_range(ebase + 0x200, (unsigned long)buf);
1852 return (void *)old_handler;
1855 static void do_default_vi(void)
1857 show_regs(get_irq_regs());
1858 panic("Caught unexpected vectored interrupt.");
1861 static void *set_vi_srs_handler(int n, vi_handler_t addr, int srs)
1863 unsigned long handler;
1864 unsigned long old_handler = vi_handlers[n];
1865 int srssets = current_cpu_data.srsets;
1869 BUG_ON(!cpu_has_veic && !cpu_has_vint);
1872 handler = (unsigned long) do_default_vi;
1875 handler = (unsigned long) addr;
1876 vi_handlers[n] = handler;
1878 b = (unsigned char *)(ebase + 0x200 + n*VECTORSPACING);
1881 panic("Shadow register set %d not supported", srs);
1884 if (board_bind_eic_interrupt)
1885 board_bind_eic_interrupt(n, srs);
1886 } else if (cpu_has_vint) {
1887 /* SRSMap is only defined if shadow sets are implemented */
1889 change_c0_srsmap(0xf << n*4, srs << n*4);
1894 * If no shadow set is selected then use the default handler
1895 * that does normal register saving and standard interrupt exit
1897 extern char except_vec_vi, except_vec_vi_lui;
1898 extern char except_vec_vi_ori, except_vec_vi_end;
1899 extern char rollback_except_vec_vi;
1900 char *vec_start = using_rollback_handler() ?
1901 &rollback_except_vec_vi : &except_vec_vi;
1902 #if defined(CONFIG_CPU_MICROMIPS) || defined(CONFIG_CPU_BIG_ENDIAN)
1903 const int lui_offset = &except_vec_vi_lui - vec_start + 2;
1904 const int ori_offset = &except_vec_vi_ori - vec_start + 2;
1906 const int lui_offset = &except_vec_vi_lui - vec_start;
1907 const int ori_offset = &except_vec_vi_ori - vec_start;
1909 const int handler_len = &except_vec_vi_end - vec_start;
1911 if (handler_len > VECTORSPACING) {
1913 * Sigh... panicing won't help as the console
1914 * is probably not configured :(
1916 panic("VECTORSPACING too small");
1919 set_handler(((unsigned long)b - ebase), vec_start,
1920 #ifdef CONFIG_CPU_MICROMIPS
1925 h = (u16 *)(b + lui_offset);
1926 *h = (handler >> 16) & 0xffff;
1927 h = (u16 *)(b + ori_offset);
1928 *h = (handler & 0xffff);
1929 local_flush_icache_range((unsigned long)b,
1930 (unsigned long)(b+handler_len));
1934 * In other cases jump directly to the interrupt handler. It
1935 * is the handler's responsibility to save registers if required
1936 * (eg hi/lo) and return from the exception using "eret".
1942 #ifdef CONFIG_CPU_MICROMIPS
1943 insn = 0xd4000000 | (((u32)handler & 0x07ffffff) >> 1);
1945 insn = 0x08000000 | (((u32)handler & 0x0fffffff) >> 2);
1947 h[0] = (insn >> 16) & 0xffff;
1948 h[1] = insn & 0xffff;
1951 local_flush_icache_range((unsigned long)b,
1952 (unsigned long)(b+8));
1955 return (void *)old_handler;
1958 void *set_vi_handler(int n, vi_handler_t addr)
1960 return set_vi_srs_handler(n, addr, 0);
1963 extern void tlb_init(void);
1968 int cp0_compare_irq;
1969 EXPORT_SYMBOL_GPL(cp0_compare_irq);
1970 int cp0_compare_irq_shift;
1973 * Performance counter IRQ or -1 if shared with timer
1975 int cp0_perfcount_irq;
1976 EXPORT_SYMBOL_GPL(cp0_perfcount_irq);
1979 * Fast debug channel IRQ or -1 if not present
1982 EXPORT_SYMBOL_GPL(cp0_fdc_irq);
1986 static int __init ulri_disable(char *s)
1988 pr_info("Disabling ulri\n");
1993 __setup("noulri", ulri_disable);
1995 /* configure STATUS register */
1996 static void configure_status(void)
1999 * Disable coprocessors and select 32-bit or 64-bit addressing
2000 * and the 16/32 or 32/32 FPR register model. Reset the BEV
2001 * flag that some firmware may have left set and the TS bit (for
2002 * IP27). Set XX for ISA IV code to work.
2004 unsigned int status_set = ST0_CU0;
2006 status_set |= ST0_FR|ST0_KX|ST0_SX|ST0_UX;
2008 if (current_cpu_data.isa_level & MIPS_CPU_ISA_IV)
2009 status_set |= ST0_XX;
2011 status_set |= ST0_MX;
2013 change_c0_status(ST0_CU|ST0_MX|ST0_RE|ST0_FR|ST0_BEV|ST0_TS|ST0_KX|ST0_SX|ST0_UX,
2017 /* configure HWRENA register */
2018 static void configure_hwrena(void)
2020 unsigned int hwrena = cpu_hwrena_impl_bits;
2022 if (cpu_has_mips_r2_r6)
2023 hwrena |= 0x0000000f;
2025 if (!noulri && cpu_has_userlocal)
2026 hwrena |= (1 << 29);
2029 write_c0_hwrena(hwrena);
2032 static void configure_exception_vector(void)
2034 if (cpu_has_veic || cpu_has_vint) {
2035 unsigned long sr = set_c0_status(ST0_BEV);
2036 write_c0_ebase(ebase);
2037 write_c0_status(sr);
2038 /* Setting vector spacing enables EI/VI mode */
2039 change_c0_intctl(0x3e0, VECTORSPACING);
2041 if (cpu_has_divec) {
2042 if (cpu_has_mipsmt) {
2043 unsigned int vpflags = dvpe();
2044 set_c0_cause(CAUSEF_IV);
2047 set_c0_cause(CAUSEF_IV);
2051 void per_cpu_trap_init(bool is_boot_cpu)
2053 unsigned int cpu = smp_processor_id();
2058 configure_exception_vector();
2061 * Before R2 both interrupt numbers were fixed to 7, so on R2 only:
2063 * o read IntCtl.IPTI to determine the timer interrupt
2064 * o read IntCtl.IPPCI to determine the performance counter interrupt
2065 * o read IntCtl.IPFDC to determine the fast debug channel interrupt
2067 if (cpu_has_mips_r2_r6) {
2068 cp0_compare_irq_shift = CAUSEB_TI - CAUSEB_IP;
2069 cp0_compare_irq = (read_c0_intctl() >> INTCTLB_IPTI) & 7;
2070 cp0_perfcount_irq = (read_c0_intctl() >> INTCTLB_IPPCI) & 7;
2071 cp0_fdc_irq = (read_c0_intctl() >> INTCTLB_IPFDC) & 7;
2076 cp0_compare_irq = CP0_LEGACY_COMPARE_IRQ;
2077 cp0_compare_irq_shift = CP0_LEGACY_PERFCNT_IRQ;
2078 cp0_perfcount_irq = -1;
2082 if (!cpu_data[cpu].asid_cache)
2083 cpu_data[cpu].asid_cache = ASID_FIRST_VERSION;
2085 atomic_inc(&init_mm.mm_count);
2086 current->active_mm = &init_mm;
2087 BUG_ON(current->mm);
2088 enter_lazy_tlb(&init_mm, current);
2090 /* Boot CPU's cache setup in setup_arch(). */
2094 TLBMISS_HANDLER_SETUP();
2097 /* Install CPU exception handler */
2098 void set_handler(unsigned long offset, void *addr, unsigned long size)
2100 #ifdef CONFIG_CPU_MICROMIPS
2101 memcpy((void *)(ebase + offset), ((unsigned char *)addr - 1), size);
2103 memcpy((void *)(ebase + offset), addr, size);
2105 local_flush_icache_range(ebase + offset, ebase + offset + size);
2108 static char panic_null_cerr[] =
2109 "Trying to set NULL cache error exception handler";
2112 * Install uncached CPU exception handler.
2113 * This is suitable only for the cache error exception which is the only
2114 * exception handler that is being run uncached.
2116 void set_uncached_handler(unsigned long offset, void *addr,
2119 unsigned long uncached_ebase = CKSEG1ADDR(ebase);
2122 panic(panic_null_cerr);
2124 memcpy((void *)(uncached_ebase + offset), addr, size);
2127 static int __initdata rdhwr_noopt;
2128 static int __init set_rdhwr_noopt(char *str)
2134 __setup("rdhwr_noopt", set_rdhwr_noopt);
2136 void __init trap_init(void)
2138 extern char except_vec3_generic;
2139 extern char except_vec4;
2140 extern char except_vec3_r4000;
2145 #if defined(CONFIG_KGDB)
2146 if (kgdb_early_setup)
2147 return; /* Already done */
2150 if (cpu_has_veic || cpu_has_vint) {
2151 unsigned long size = 0x200 + VECTORSPACING*64;
2152 ebase = (unsigned long)
2153 __alloc_bootmem(size, 1 << fls(size), 0);
2155 #ifdef CONFIG_KVM_GUEST
2156 #define KVM_GUEST_KSEG0 0x40000000
2157 ebase = KVM_GUEST_KSEG0;
2161 if (cpu_has_mips_r2_r6)
2162 ebase += (read_c0_ebase() & 0x3ffff000);
2165 if (cpu_has_mmips) {
2166 unsigned int config3 = read_c0_config3();
2168 if (IS_ENABLED(CONFIG_CPU_MICROMIPS))
2169 write_c0_config3(config3 | MIPS_CONF3_ISA_OE);
2171 write_c0_config3(config3 & ~MIPS_CONF3_ISA_OE);
2174 if (board_ebase_setup)
2175 board_ebase_setup();
2176 per_cpu_trap_init(true);
2179 * Copy the generic exception handlers to their final destination.
2180 * This will be overriden later as suitable for a particular
2183 set_handler(0x180, &except_vec3_generic, 0x80);
2186 * Setup default vectors
2188 for (i = 0; i <= 31; i++)
2189 set_except_vector(i, handle_reserved);
2192 * Copy the EJTAG debug exception vector handler code to it's final
2195 if (cpu_has_ejtag && board_ejtag_handler_setup)
2196 board_ejtag_handler_setup();
2199 * Only some CPUs have the watch exceptions.
2202 set_except_vector(23, handle_watch);
2205 * Initialise interrupt handlers
2207 if (cpu_has_veic || cpu_has_vint) {
2208 int nvec = cpu_has_veic ? 64 : 8;
2209 for (i = 0; i < nvec; i++)
2210 set_vi_handler(i, NULL);
2212 else if (cpu_has_divec)
2213 set_handler(0x200, &except_vec4, 0x8);
2216 * Some CPUs can enable/disable for cache parity detection, but does
2217 * it different ways.
2219 parity_protection_init();
2222 * The Data Bus Errors / Instruction Bus Errors are signaled
2223 * by external hardware. Therefore these two exceptions
2224 * may have board specific handlers.
2229 set_except_vector(0, using_rollback_handler() ? rollback_handle_int
2231 set_except_vector(1, handle_tlbm);
2232 set_except_vector(2, handle_tlbl);
2233 set_except_vector(3, handle_tlbs);
2235 set_except_vector(4, handle_adel);
2236 set_except_vector(5, handle_ades);
2238 set_except_vector(6, handle_ibe);
2239 set_except_vector(7, handle_dbe);
2241 set_except_vector(8, handle_sys);
2242 set_except_vector(9, handle_bp);
2243 set_except_vector(10, rdhwr_noopt ? handle_ri :
2244 (cpu_has_vtag_icache ?
2245 handle_ri_rdhwr_vivt : handle_ri_rdhwr));
2246 set_except_vector(11, handle_cpu);
2247 set_except_vector(12, handle_ov);
2248 set_except_vector(13, handle_tr);
2249 set_except_vector(14, handle_msa_fpe);
2251 if (current_cpu_type() == CPU_R6000 ||
2252 current_cpu_type() == CPU_R6000A) {
2254 * The R6000 is the only R-series CPU that features a machine
2255 * check exception (similar to the R4000 cache error) and
2256 * unaligned ldc1/sdc1 exception. The handlers have not been
2257 * written yet. Well, anyway there is no R6000 machine on the
2258 * current list of targets for Linux/MIPS.
2259 * (Duh, crap, there is someone with a triple R6k machine)
2261 //set_except_vector(14, handle_mc);
2262 //set_except_vector(15, handle_ndc);
2266 if (board_nmi_handler_setup)
2267 board_nmi_handler_setup();
2269 if (cpu_has_fpu && !cpu_has_nofpuex)
2270 set_except_vector(15, handle_fpe);
2272 set_except_vector(16, handle_ftlb);
2274 if (cpu_has_rixiex) {
2275 set_except_vector(19, tlb_do_page_fault_0);
2276 set_except_vector(20, tlb_do_page_fault_0);
2279 set_except_vector(21, handle_msa);
2280 set_except_vector(22, handle_mdmx);
2283 set_except_vector(24, handle_mcheck);
2286 set_except_vector(25, handle_mt);
2288 set_except_vector(26, handle_dsp);
2290 if (board_cache_error_setup)
2291 board_cache_error_setup();
2294 /* Special exception: R4[04]00 uses also the divec space. */
2295 set_handler(0x180, &except_vec3_r4000, 0x100);
2296 else if (cpu_has_4kex)
2297 set_handler(0x180, &except_vec3_generic, 0x80);
2299 set_handler(0x080, &except_vec3_generic, 0x80);
2301 local_flush_icache_range(ebase, ebase + 0x400);
2303 sort_extable(__start___dbe_table, __stop___dbe_table);
2305 cu2_notifier(default_cu2_call, 0x80000000); /* Run last */
2308 static int trap_pm_notifier(struct notifier_block *self, unsigned long cmd,
2312 case CPU_PM_ENTER_FAILED:
2316 configure_exception_vector();
2318 /* Restore register with CPU number for TLB handlers */
2319 TLBMISS_HANDLER_RESTORE();
2327 static struct notifier_block trap_pm_notifier_block = {
2328 .notifier_call = trap_pm_notifier,
2331 static int __init trap_pm_init(void)
2333 return cpu_pm_register_notifier(&trap_pm_notifier_block);
2335 arch_initcall(trap_pm_init);